Capsule forming apparatus with fluid metering valve



Sept. 9, 1969 L. F. HANSEN CAPSULE FORMING APPARATUS WITH FLUID METERING VALVE Filed Dec. 23, 1966 2 Sheets-Sheet l \NHII/I, W A o v 2L mw I I H w. f k w INVENTOR lo ud Z'Hansen ATTORNEYS Sept. 9, 1969 LQF. HANSEN CAPSULE FOF(MING APPARATUS WITH FLUID METERING VALVE Filed Dec. 23, 1966 2 Sheets-Sheet 2 United States Patent US. Cl. 53-184 9 Claims ABSTRACT OF THE DISCLOSURE A fluid metering valve which is particularly adapted for use in delivering doses of liquid medicament to the die roll of a gelatin capsuling machine. A rotatable valve core is mounted in a valve block and is actuated by a rotary solenoid to intermittently open and close the valve passages. The actuation of the rotary solenoid is controlled by a microswitch actuated in response to movement of the cavities in the die roll. The metering valve is mounted adjacent the die roll, and nozzles extending from the valve deliver liquid directly and precisely to each cavity thereof when the valve passages are opened.

Liquid pharmaceutical products are often dispensed in soft shell gelatin capsules. These are made by filling with liquid a cavity lined with a gelatin film, sealing the cavity opening with a separate layer of gelatin film, and then removing the resulting gelatin capsule from the cavity.

An apparatus for thus forming gelatin capsules is disclosed in US. Patent No. 2,690,038 assigned to the assignee of the present invention. -In that apparatus, the liquid medicament is fed in a continuous, unbroken stream to the cavities in the cavity die roll by means of a rotary gear pump. The continuous feeding of liquid in this manner, however, has not been fully satisfactory under all conditions. When liquid medicament flows in an uninterrupted stream, it not only fills each cavity in the die roll but also spills onto the gelatin film adjacent each cavity. This may result in poorly sealed capsules which leak or become contaminated during storage. Moreover, the liquid medicament which is spilled adjacent the cavities cannot be readily recovered and the loss of active liquid ingredients has proven costly.

In an effort to overcome the disadvantages of continuous liquid feeding, a piston-operated metering pump has been substituted for the rotary gear pump shown in the above patent, to produce an interrupted liquid flow intended to fill only the cavities in the cavity die roll. The piston-operated metering pump, however, has serious disadvantages. The reciprocating speed of a piston-operated pump is limited, thus limiting the number of doses of liquid it can deliver to the cavity die roll per unit time with concomitant limitations on production rate. Moreover, when operated near the limit of its reciprocating speed, a piston metering pump tends to deliver a constant rather than interrupted liquid flow, thus defeating its purpose in a capsuling machine.

Accordingly, an object of the present invention is to provide a fluid metering valve.

Another object of the invention is to provide a valve of the above character which is adapted for intermittently delivering doses of liquid to the die roll of a gelatin capsuling machine.

Another object of the invention is to provide a valve of the above character which minimizes waste of liquid medicament and which enables the production of capsules securely sealed against leakage.

Another object of the invention is to provide a valve Patented Sept. 9, 1969 ice of the above character capable of rapid and economical operation.

A still further object of the invention is to provide a valve of the above character which is simple, inexpensive, and reliable in use.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a side elevation view of the fluid metering valve of the invention, mounted on a portion of a gelatin capsuling machine shown partly in section.

FIGURE 2 is a slightly enlarged top sectional view of the invention taken along the line 22 of FIGURE 1.

FIGURE 3 is an end sectional View of the metering valve taken along the line 3--3 of FIGURE 2 showing the valve in open and closed (dotted-line) positions.

FIGURE 4 is an exploded perspective View of the metering valve of the invention.

FIGURE 5 is a top plan view of the microswitch assembly of the invention.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to FIGURE 1, the fluid metering valve of the invention is shown generally at 10. It is mounted on an extension 11 of the frame of a gelatin capsuling machine of the type shown in US. Patent No. 2,690,038 adjacent the nip formed by the cavity die roll 12 and the seal roll 14. When intermittently actuated by a microswitch 16 in response to movement of die roll 12 as more fully described hereinbelow, valve 10 briefly interrupts the stream of liquid being continuously fed thereto by a gear pump 18 through tubing 20, and then reopens to again allow free passage of liquid. Thus, through coordination of the actuation of valve 10 with the movement of cavity die roll 12, discrete doses of liquid 22 are delivered to each of the vacuum-formed gelatin lined cavities 24 therein. The cavities are then sealed as described in the above-mentioned patent to produce gelatin capsules which are suitable for pharmaceutical use.

Referring now to FIGURE 4, the fluid metering valve comprises a valve block 26 preferably formed of a corrosion-resistant material such as stainless steel, although other suitable materials such as plastic may be used. Normally, the other members forming the metering valve will be of the same material as block 26. Block 26 is provided with a large longitudinal bore 28 extending the length thereof. A plurality of smaller passages 3036 are formed through block 26 perpendicular to and intersecting the large bore 28. Block 26 is preferably of rectangular shape as shown; however, other suitable shapes will suggest themselves to those skilled in the art.

A valve core 38 is provided for mounting within the bore 28 of block 26. It comprises a cylindrical portion 40 having a diameter sufficiently less than that of bore 28 to permit ready rotation therein; however, the diameters of cylindrical portion 40 and bore 28 should be sufiiciently close to prevent leakage of liquid between their confronting surfaces. A plurality of passages 30a- 36a, equal in number to passages 30-36 in block 26 and spaced so as to register therewith in assembly, are formed diametrically through valve core 38, and one end 42 of core 38 is turned down to form a shaft portion. A plate mitting rotation thereof is mounted adjacent the other 3 end. A pin 46 protrudes from the end adjacent plate 44 for attachment to a return spring 47 (FIGURE 1) as is more fully discussed below. Valve core 38 is mounted in block 26 with plate 44 abutting one end 48 thereof and with shaft portion 42 protruding from the other end.

A second plate 50 having a bore 52 which supports shaft portion 42 of valve 38 while permitting rotation thereof is mounted over protruding portion 42 and against the other end of block 26.

A maniold plate 54 having a plurality of passages 30b 36b formed therethrough equal in number to and spaced to register with passages 30-36 in block 26, is fastened to the rear surface 56 thereof. Tubular connectors 58 extend from the back surface 60 of plate 54 in alignment with each passage 3012-3611 to facilitate the connection of tubing 20 from gear pump 18 as is shown in FIGURE 1.

A nozzle plate 62 is fastened to the front surface 64 of block 26. Nozzle plate 62 has a plurality of passages 30c-36c formed therethrough equal in number and positioned to register with the corresponding passages 3036 in block 26. An elongated nozzle 66 extends from the front surface 68 of plate 62 in communication with each of the passages 30c-36c therein as shown in FIGURES 2 and 3.

Referring now to FIGURE 2, in assembly the corresponding passages through manifold plate 54, block 26, valve core 38, and nozzle plate 62 communicate to form continuous passages capable of transmitting liquid entirely through the valve assembly 10. As shown in FIG- URE 3, however, valve core 38 can be rotated (dotted lines) to interrupt the flow of liquid by means of a rotary solenoid 63 which is fixedly secured to an extension 64 of valve core 38 adjacent pin 46 as shown in FIGURE 2.

Rotary solenoid 63 is actuated by a microswitch 16 (FIGURE 1) positioned adjacent cavity die roll 12 on an arm 67. Arm 67 is pivotably supported on the capsuling machine frame 68 and can be secured in a desired position with relation to cavity die roll 12 by means of a screw 70 passing through slot 72 and into frame 68.

Microswitch 16 is mounted to a sliding block 73 which is slidably mounted on arm 67 by means of a pin 74 passing through slot 75 as shown in FIGURE 5. A bolt 76 having a knurled knob 77 passes through arm 67 and is threadably engaged through sliding block 73. By turning knob 77 in either a clockwise or counterclockwise direction, microswitch 16 can be moved either toward or away from roll 12 as shown by the arrows in FIG- URE 5.

Microswitch 16 is actuated by a feeler 78 positioned to ride over the surface of the upstanding rim 80 surrounding each cavity of the die roll 12. By rotatably adjusting arm 67 about pin 70, feeler 78 can be positioned so that it is actuated at the proper instant during movement of die roll 14 as is more fully described below. Further, by means of knob 77, the pressure of feeler 78 against rim 80 can either be increased or decreased and thus the sensitivity of microswitch 78 is adjustable as desired.

While the fluid metering valve has been shown with four liquid passages and four nozzles to correspond with a cavity die roll having four rows of cavities, it will be understood that the number and spacing of the passages and nozzles can be varied to correspond to any given die roll configuration. In addition, the passages 30a-36a through valve core 38 have been shown placed in line so as to result in simultaneous opening and closing of the fluid metering valve passages; however, it will be understood that the passages through valve core 38 may be staggered across the periphery of cylindrical portion 40 so as to provide sequential opening and closing of the fluid metering valve passages when such a procedure is desirable.

SEQUENCE OF OPERATION As in shown in FIGURE 1, the fluid metering valve is mounted on extension 11 of the gelatin-capsulmg machine frame adjacent the nip of rolls 12 and 14 by means of a bracket 82 secured to both extension 11 and rotary solenoid 63. The placement of valve 10 and the configuration of nozzles 66 should be such that liquid medicament is delivered to each cavity 24 without unnecessary splashing and without danger of contact between roll 12 and nozzles 66.

Liquid medicament is continuously fed to the metering valve 10 from a supply source (not shown) through tubing 20 by means of a rotary gear pump 18.

Return spring 47 is affixed at one end to pin 46 on valve core 38 and at its other end to extension 11. The position of pin 46 and the length of spring 47 are adjusted so as to maintain valve core 38 in an open position as shown by the solid lines in FIGURES 3. In the open position, liquid can flow freely through rotary valve 10 to be delivered to the individual cavities 24 by means of nozzles 66 (FIGURE 1).

As die roll 12 rotates in a clockwise direction (FIG- URE 1), microswitch feeler 78 is intermittently actuated by contact with the outer surface of the rim surrounding each cavity 24. Actuation of microswitch 16 in turn actuates rotary solenoid 63 which revolves valve core 38 about 45 degrees to its closed position which is shown dotted in FIGURE 3. Between actuations by microswitch 16, valve core 28 is returned to its open position by the biasing force of return spring 47. The small degree of movement required to close and open rotary valve 10 permits relatively rapid operation of the gelatin capsuling machine to be attained with concomitant rapid production of gelatin capsules.

It can thus be seen that the position of microswitch 16 should be adjusted with relation to die roll 12 so that actuation thereof occurs at the time the portions of die roll 12 between cavities 24 are passing under nozzles 66. In this manner, discrete doses of liquid medicament are delivered to each cavity 24, while liquid flow is cut off to the portions of roll 12 between cavities 24 thus minimizing waste and eliminating the sealing problem encountered in gelatin capsules manufactured with prior art apparatus.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained and, since certain changes may be made in the above article without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In an apparatus requiring the intermittent delivery of fluid to a moving member, a valve mechanism for metering fluids comprising:

(A) a hollow valve block having inlet and outlet means:

(B) a valve core (1) movably mounted in substantially fluid-tight assembly within said valve block, and

(2) having means forming at least one passage therethrough,

(a) said passage communicating with and interconnecting both said inlet and outlet means at at least one position in the movement of said valve core;

(C) means intermittently actuating said valve core in response to movement of said moving member to move said passage out of communication with said inlet and outlet means; and

(D) means for returning said valve core between each said actuation to a position wherein said passage communicates with and interconnects said inlet and outlet means.

2. Apparatus as defined in claim 1 wherein said valve has a plurality of corresponding pairs of inlets and outlets and a plurality of passages through said valve core, each said passage communicating with and interconnecting one inlet and outlet pair at one position in the movement of said valve core.

3. Apparatus as defined in claim 2 including a nozzle communicating with each said outlet for delivering fluid from said valve to a predetermined point on said moving member.

4. In an apparatus for forming liquid-filled capsules which comprises a cavity die roll and a seal roll which cooperate to form a sealed capsule, and pumping means for feeding said liquid to the vicinity of said rolls, a liquid metering valve comprising:

(A) a hollow valve block (1) positioned between said pumping means and said rolls, and

(2) having inlet and outlet means (B) a valve core 1) rotatably mounted in substantially liquidtight assembly within said valve block, and

(2) having means forming at least one passage therethrough,

(a) said passage communicating with and interconnecting both said inlet and outlet means at at least one position in the rotation of said valve core,

(C) driving means for rotating said valve core,

(D) discharge means for delivering liquid from said outlet means to the cavities in said cavity die roll, and

(E) means intermittently actuating said driving means in response to movement of said cavity die roll to rotate said passage out of communication with said inlet and outlet means and prevent liquid flow to portions of said die roll adjacent said cavities.

5. An apparatus as defined in claim 4 and further including means for returning said valve core between each said actuation to a position wherein said passage communicates with and interconnects said inlet and outlet means to permit liquid flow to said cavities.

6. In an apparatus for forming liquid-filled capsules which comprises a cavity die roll and a seal roll which cooperate to form a sealed capsule, and pumping means for feeding said liquid to the vicinity of said rolls, a liquid metering valve comprising:

(A) a hollow valve block 1) positioned between said pumping means and said rolls, and

(2) saving inlet and outlet means,

(B) a valve core (1) rotatably mounted in substantially liquid-tight assembly within said valve block, and

(2) having means forming at least one passage therethrough,

(a) said passage communicating with and interconnecting both said inlet and outlet means at at least one position in the rotation of said valve core,

(C) driving means for rotating said valve core,

(D) discharge means for delivering liquid from said outlet means to the cavities in said cavity die roll, and

(E) means intermittently actuating said driving means in response to movement of the cavities in said cavity die roll to rotate said passage relative to said inlet and outlet means.

7. A liquid metering valve as defined in claim 6 having a plurality of corresponding pairs of inlets and outlets and a plurality of passages through said valve core, each said passage communicating with and interconnecting one inlet and outlet pair at one position in the rotation of said valve core.

8. An apparatus as defined in claim 6 wherein said discharge means comprises at least one nozzle in communication with said outlet means and extending to a point adjacent the path of movement of the cavities in said cavity die roll.

9. In an apparatus for forming liquid-filled capsules which comprises a cavity die roll and a seal roll which cooperate to form a sealed capsule, and pumping means for feeding said liquid to the vicinity of said rolls, a liquid metering valve comprising:

(A) a hollow valve block 1) positioned between said pumping means and said rolls, and (2) having inlet and outlet means, (B) a valve core (1) rotatably mounted in substantially liquid-tight assembly within said valve block, and (2) having means forming at least one passage therethrough (a) said passage communicating with and interconnecting both said inlet and outlet means at at least one position in the rotation of said valve core,

(C) driving means for rotating said valve core comprising a rotary solenoid mounted to said valve core to rotate said passage out of communication with said inlet and outlet means upon actuation thereof,

(D) a return spring biasing said valve core to an open position between each said actuation of said rotary solenoid, and

(E) discharge means for delivering liquid from said outlet means to the cavities in said cavity die roll.

References Cited UNITED STATES PATENTS 2,387,747 10/1945 Cowley 53l84 X 2,520,591 8/1950 Wilmarth 137-595 2,624,164 1/1953 Donofrio 53-184 X 2,690,038 9/1954 Stirn et al. 53184 X 3,224,462 12/1965 Lopker 137625.19

THERON E. CONDON, Primary Examiner R. L. SPRULL, Assistant Examiner US. Cl. X.R. 

